Chapter 11 notes Flashcards
(138 cards)
1
Q
Microbes are _______
A
ubiquitous
2
Q
Are most environments sterile or not sterile
A
not sterile
3
Q
Define fomite
A
any inanimate object that, when contaminated with or exposed to infectious agents, can transfer disease to a new host
4
Q
What can be found in drinking water
A
numerous diseases are from pathogens found in drinking water
5
Q
What is the process of boiling water for disinfection
A
exposure of materials to 30+ minutes in boiling water will kill most non-spore forming pathogens
6
Q
What is the mode of action for boiling water for disinfection
A
denature proteins and alter cell membranes
7
Q
Will boiling water sterlize?
A
NO just disinfect
8
Q
What can survive boiling water
A
Endospores
9
Q
Will a fridge filter remove pathogens from…
Euk
Pro
Virus
A
most
most
no
10
Q
What is the process of filtration
A
strain fluid or air through a porous membrane to physically remove microbes
11
Q
What is the mode of action of filtration
A
physical separation, not destroying the microbe
12
Q
Filtration is used to sterilize heat sensitive ______ and ________ in hospital isolation units
A
liquids; air
13
Q
Filtration is used in water ____
A
purification
14
Q
Define contaminant
A
microbes present that are undesirable or unwanted
15
Q
What 3 things influence how clean is clean
A
- object of interest
- application for object
- potential pathogens that may infect the item, their level of resistance to control methods
16
Q
What are the physical methods of microbial control
A
heat
filtration
desiccation
radiation
cold
17
Q
What are the two types of chemical methods of microbial control
A
chemo/drugs
biocides
18
Q
What 2 microbes are highest level of resistance
A
prions
bacterial endospores
19
Q
Define prions
A
protein infectious particles
20
Q
What are the microbes in the moderate resistance level
A
protozoan cysts
naked viruses
bacteria with no endospore but resistant walls (staphyloccocus)
21
Q
What are the microbes in the least resistant level
A
most bacterial vegetative cells
fungal spores and hyphae
protozoan trophozoite
enveloped viruses
yeast
22
Q
Define anthrax spores
A
a protective layer called endospore by which it can remain inactive for many years and under suitable environmental condition it can revive and become infectious
23
Q
No microbial adaptation or cellular structure can compare to the resiliency of the _______ ________ (or _____ _____)
A
bacterial endospore; simple spore
24
Q
Is an endospore considered “dead”
A
metabolically inert but can become vegetative cell
25
Define sterilization
process that destroys all viable endospores
26
Define microbial death
loss of reproductive capacity
27
What is the microbial death curve
describes the process, often plotted as semilog function
death continues in a log manner as time of exposure increases
28
The amount of time it takes for a specific protocol to produce a one order of magnitude decrease in the number of organisms or dealth of 90% of the population is called
decimal reduction time or D-value
29
Define microbial load
the size of the microbial population, also can be thought of as the total number of microbes at the beginning of a disinfection treatment
30
Define filtration
separation process the removes larger molecules or cells from air or liquids
31
Define incineration
the destruction of microbes by burning or turning to ash
32
Define germination
the process of something becoming metabolically active again (e.g. endospore becoming a vegetative cell)
33
these chemical control agents can be used in antisepsis products and consist of a small organic compound containing an OH group
alcohols
34
Hydrogen peroxide is an example of this
peroxygens
35
What is sepsis
growth of microbes in human blood and other tissues
36
What is microbicide
agent aimed at killing or destroying microbes; general term to include all microbes
37
What is an autoclave
a piece of equipment that uses high temperatures, steam, and pressure to control microbial growth
38
examples of this include cl2, NaOCl, and I2
halogens
39
What is the surfactant used in a variety of washing and cleaning products
soap
40
What is the process of making something free from microbes, viruses, and endospores, destroying any possibility of viability in the process
sterilization
41
What is a vegetative cell
endospore revitalized when favorable conditions arise, they break dormancy and become this
42
What is the permanent loss of reproductive capacity for a microbe, even under optimal growth conditions called
microbial death
43
Formalin is an example of this and is commonly used to preserve biological specimens
aldehydes
44
What are agents that halt microbial growth without killing the cells, growth may resume if the control agents are removed
microbistatic
45
What is the method of microbial control originally developed by louis pasteur
pasteurization
46
What is the use of a physical process or chemical agent to destroy most microbes called
disinfection
47
These are widely used chemical control agents, chemical features include a benzene ring with an OH group
phenolics
48
What is the cleansing technique that removes debris, soil, microbes, and toxins and in this way reduces the potential for infection and spoilage, this technique may not directly target the microbe but still can result in control of its growth
sanitization
49
This is a dormant, tough, and non-reproductive structure produced by some bacteria to withstand extreme or harsh environmental conditions
Endospore
50
What is the use of edible chemicals to prevent microbial growth in food called
preservatives
51
What is the agents that kill microbes and explode the cells in the process
Microbilytic
52
WHat is the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization called
radiation
53
What is the goal in disinfection
to destroy vegetative pathogens but not bacterial endospores
54
Disinfection usually occurs on __________ things
non-living things
55
Define antisepsis
use of chemicals on skin or human tissues to inhibit or eliminate microbial growth but not equal to sterilization
56
Germicides are agents that kill pathogenic microbes and can be on ______ living and non living things
can
57
For temperature control:
temps below the minimum growth temperature is ____________
microbistatic
58
For temperature control:
temps exceeding the maximum growth temperature is _____________
microbicidal
59
Is moist heat or dry heat more effective
moist heat
60
Is boiling water for disinfection sporicidal
no
61
Is pasteurization sporicidal
no
62
What is the mode of action for pateurization
denatures proteins and alters cell membrane
63
What is the process of pasteurizaiton
use of elevated heat for prolonged time to reduce microbial load and destroy pathogens, followed by rapid cooling to minimize damage to food or liquid
64
The change in environments disrupts what in regards to protein denaturing
protein shape and function
65
What is the mode of action of autoclaves
denature proteins and alter cell membrane
66
What is the process of incineration
use of a flame or electric heating coil to ignite and reduces microbes to ashes and gas
67
What is the mode of action of incineration
destroy by burning
68
inoculation loop through a flame is an example of incineration (T/F)
T
69
What is the process of ovens
heath to 180 C for 2 to 4 hours
70
What is the mode of action of ovens
dehydration, denatures proteins, and alters membranes
71
Is incineration sporicidal
yes
72
are ovens sporicidal
yes at prolonged time
73
Define food poisoning
disease caused by injecting contaminated food
74
What is the type of food poisoning for exoproduct produced by microbes causes diesase
food intoxication
75
What is the type of food poisoning for microbe itself cause disease
food infection
76
Can the following be microbes that are food-borne pathogens
bacteria
protozoa
viruses
algae
yes
yes
yes
usually no
77
What are the 4 good practices to reduce incorporation of potentially pathogenic microbes into food
clean
separate
cook
chill
78
What is the mode of action of cold
inhibits metabolism (slows or arrests cell division)--freezing may lyse cells
79
What is the process of desiccation
dry out the sample
80
What is the mode of action of desiccation
water is essential for metabolism and survival
81
Is desiccation effective
not really
82
Define radiation
energy emitted from atomic particles and dispersed at high velocity through matter or space
83
Define ionizing radiation
consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or a molecule by detaching electrons from them
84
What are examples of ionizing radiation
nuclear radiation, gamma rays, x-rays
85
What is the process of ionizing radiation
shine radiation source on sample or expose sample to EM waves
86
What is the mode of action of ionizing radiation
strong enough to pass into the cell where it alters molecular structure and damages cell component (double stranded breaks in DNA)
87
Ionizing radiation has ____________ power
high penetrating
88
Is ionizing radiation sporicidal
yes
89
What are examples of non ionizing radiation
UV light or sunlight
90
What is the mode of action of non ionizing radiation
introduces thymine dimers leading to DNA mutation
91
Non ionizing radiation has ___________ power
low penetrating
92
is non ionizing radiation sporicidal
yes
93
What is an example of non ionizing a liquid
UV water treatment
94
What is the target microbes for chlorine
sporicidal (slowly)
95
What is the level of germicidal activity for chlorine
intermediate
96
What is the level of toxicity for chlorine
gas is highly toxic; solution irritates skin
97
what is chlorine inactivated by and when is it unstable
inactivated by organics; unstable in sunlight
98
What is the target microbes for iodine
sporicidal (slowly)
99
What is the level of germicidal activity for iodine
Intermediate
100
What is the toxicity for iodine
can irritate tissue; toxic if ingested
101
What is the target microbe of phenolics
some bacteria, viruses, fungi
102
What is the level of germicidal activity of phenolics
low to intermediate
103
What is the toxicity of phenolics
can be absorbed by skin; can cause CNS damage
104
What is the target microbes of alcohols
most bacteria, viruses, fungi
105
What is the level of germicidal activity of alcohols
intermediate
106
What is the toxicity of alcohols
toxic if ingested; a mild irritant; dries skin
107
What is the target microbes of hydrogen peroxide
sporicidal
108
What is the level of germicidal activity of hydrogen peroxide
high (sterilant)
109
What is the toxicity of hydrogen peroxide
toxic to eyes; toxic if ingested
110
What is the target microbe soaps
certain very sensitive species
111
What is the level of germicidal activity of soaps
very low
112
What is the toxicity of soaps
nontoxic; few if any toxic effects
113
What is the target microbe of ethylene oxide gas
sporicidal
114
What is the level of germicidal activity of soaps
high (sterilant)
115
What is the toxicity of ethylene oxide gas
very dangerous to eyes, lungs, carcinogenic
116
What is the mode of action of halogens
oxidation and breaks down proteins, damages DNA, RNA, and fatty acids
117
What is the mode of alcohols
work by rapidly denaturing proteins (which inhibits cell metabolism) and by disrupting membranes (which leads to cell lysis)
118
What is the mode of aldehydes
kill by alkylating proteins and DNA
119
What is the mode of action of peroxygens
produce highly reactive hydroxyl-free radicals that damage protein and DNA while also decomposing to O2 gas--toxic to anaerobes
120
What is the mode of action of gases (ethylene oxide)
alkylating DNA, RNA, and protein
121
What is the mode of action of soaps and detergents
surfactants insert in the lipids bilayer and disrupt it to create abnormal channels that alter permeability and cause leakages
122
Would surfactants be more disruptive against enveloped or unenveloped viruses
enveloped
123
What chemicals could be added to soaps to make them "germicidal"
phenolics
124
What is the mode of action of preservatives
often weak acids that disrupt membrane functions, also solutes like salt and sugar produce conditions of high osmolarity
125
What do antibiotics, antivirals, and antifungals do
they are toxic or inhibits growth to a very specific and selective group of microbes
126
Antibiotics, antivirals, and antifungals are usually __________ products
natural
127
What do antibiotics, antivirals, and antifungals target
target the processes of DNA replication, transcription, and translation
128
How would we sterlize room air
filtration
129
How would we sterilize heat sensitive drugs
radiation
130
How would we sterilize a pot of soil
gamma radiation
131
How would we sterilize a pot of soil
gamma radiation
132
How would we sterlize cloth dressings
radiation
133
How would we sterilize a glass bottle with media
autoclave
134
How would we sterilize fruit juice
pasteurization
135
Spores are _____________ to disinfectants because the spore coat and cortex act as a barrier
resistant
136
What makes bacteria more resistant to antimicrobials than the same bacteria
biofilms
137
Mycobacteria have a ______ cell wall that prevents disinfectant entry
waxy
138
more time means it can be __________ effective
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